[unreadable] Electrocardiography (ECG) is one of a triad of the oldest clinical tools (stethoscope 1816, radiography 1895, ECG 1902) still in use in the evaluation of patients with suspected cardiac disease, and remains one of the most cost-effective cardiographic tools available to the clinician. Accurate electrocardiographic recognition of arrhythmias facilitates appropriate therapy and avoids complications that could result from either failure to recognize the arrhythmia or failure to employ appropriate management. [unreadable] [unreadable] The objective is to develop a novel, highly interactive, Internet-based teaching and testing program on arrhythmia recognition of electrocardiograms (ECGs) for medical trainees, utilizing actual patient data and custom animations. Three components-tutorial animations, rapid assessment skills of printouts, and preparation for board exams-will improve medical trainees' ECG interpretation skills, and improve them more quickly than traditional education. In addition, the development of an authoring tool will allow instructors to create new content rapidly from their own ECG collection for teaching and testing. Internet distribution of the program will allow trainees and instructors to use the program without any special hardware or software other than a personal computer and a browser like Internet Explorer or Netscape. For situations where access to the Internet is not practical, a stand-alone version will be available for local networks or for single computers. To measure the program's effectiveness in improving skills, in Phase I the program will be evaluated in a small pilot study of medical trainees at two teaching hospitals, expanding to several other sites in Phase II. [unreadable] [unreadable] The market for effective ECG training software is large, and includes residency training programs, cardiology fellowships, as well as advanced practice nursing programs. As certification for ECG over-reading privileges becomes established in more health care facilities and networks, the demand for efficient, cost-effective training for graduate physicians will increase for healthcare points of entry: emergency departments, urgent care clinics, and primary care. Large healthcare networks in particular are highly motivated to lower the number of false positive/false negative diagnoses from ECG interpretation. [unreadable] [unreadable]